Fluid-actuated clutch and brake



April 13, 1965 R. JEwsoN 3,177,994

FLUID-ACTUTED CLUTCH AND BRAKE Filed Aug. s. 1962 LEEU. /14 2 ATTORNEYSUnited States Patent O 3,177,994 FLUEDACTUATED CLUTCH AND BRAKE Rowland`lawson, Toledo, Ghia, assigner to The Bunting Brass and Bronze Company,Toledo, Uhio, a corporation of Qhio Fiied Aug. 3, 1962, Ser. No. 214,626Claims. (Ci. 192-18) This invention relates to a device for thetransmission of power between a driving shaft and a driven shaft, andmore particularly to a fluid actuated control device operable at thewill of the operator for frictionally connecting and disconnecting thedriving and driven shafts, together with braking means operablecoincidentally with the disconnection of a driving and driven shaft toapply a braking force and stop the rotation of the driven shaft. In thepreferred form of the invention, a pneumatically operated piston is usedto cause connection of the clutch and alternate operation of the brakemechanism.

Combination brake and clutch control devices have been used for manyyears. Such devices are particularly suitable for use with machine toolsin which frequent stopping and starting operations are necessary. Withmost lathes, for example, it is undesirable to stop and start theelectric motor which drives the lathe since the starting current of thecommon electric motor is generally about 200% of the full load currentso that a surge occurs each time the motor is started. This causesunnecessary heating of the motor and unnecessary power drain. It hasbeen found desirable, therefore, to permit the motor to run continuouslyand to interpose a separate mechanism which will permit the continuouslyoperating motor to be connected or disconnected to the driven shaftwhich may be the lathe spindle drive.

Presently known drive control mechanisms are difficult to dismantle andrepair since various fluid connections must be interrupted and variousof the brake and clutch elements must be dismantled before the mechanismcan be taken apart for reworking.

The primary object of the present invention is to provide a clutch andbrake control device which may be readily dismantled for replacement ofparts and for other repairs.

Another object of the invention is to completely eliminate all springloaded elements which may be subject to deterioration.

Another object of the invention is to provide a clutch and brake controldevice which may be readily interposed in the power train of a machinetool without significant modification of the existing elements.

Other objects and advantages of the invention will becorne apparent fromthe following description of a preferred form thereof, reference beinghad to the accompanying drawings in which:

FIG. 1 is a longitudinal cross-sectional view of a clutch and brakeassembly embodying the present invention;

FIG. 2 is a cross section on the line 2-2 of FIG. 1; and

FIG. 3 is a fragmentary, cross-sectional view taken along the line 3-3of FIG. 2.

Referring to the drawings, and more particularly to FIG. 1, a clutch andbrake assembly according to the invention is indicated generally at andincludes a spindle or driven shaft 12 extending from one end of thehousing 14 and a drive shaft 16 connected to a driving motor 1S. Thedrive shaft 16 is keyed to and drives an input clutch cup 20 which hasan elongated collar 22 affixed to the shaft 16 by setscrews 24 toprevent relative axial movement between the motor shaft and the collar22. The clutch cup 2i) is provided with an inner ball race 26 whichsupports an inner end of the driven shaft 12 in EdT/,94 Patented Apr.i3, 1%65 ICC alignment with the drive shaft 16. The clutch cup also hasa plurality of spaced notches or cut-outs 23 around the perimeter of anannular flange portion 30, which notches receive tabs 32 of drivingclutch discs 34. The drive discs 34 always rotate with the clutch cup2i) because of the cooperation between the tabs 32 and the notches 23. Aseries of driven clutch discs 36 are located between the drive discs 34and are connected to the driven shaft by a key 38. The discs 345 and 36can rotate freely with respect to one another except when forcedtogether into driving engagement against an annular backing ring bymeans of a thrust retainer 42. Clutches of this nature are known in theart and the elements, per se, form no part of the present invention.

The retainer 42 has an annular bearing iiange 44 which supports a thrustbearing 46 including an outer race 48 held by a press iit in engagementwith the flange 44 and including an inner race Si) which is spaced fromthe driven shaft 12. When the thrust bearing is moved toward the left bya force exerted on the inner race 50 the retainer 42 is moved and exertsa squeezing or clutching force on the discs 34 and 36, moving themtogether against the backing ring 40. The discs 34 and 36 then rotatetogether and the drive and driven shafts are connected.

The present invention provides a simple and highly effective uidactuated control device for the clutch and for a brake which will besubsequently described. The control device is designated generally 52and includes a cylinder 54 formed by an end plate 56 and a cylinderhousing 58. As shown in FIG. 1, these components are held together by aplurality of screws 59 and have cooperating circumferential recesses ornotches 60 which constitute, in effect, an interrupted thread and enablethe components to be easily assembled with arcuate supports 62 which areaixed to the side walls of the housing 14.

The manner of assembly of the components which the present inventionprovides is extremely fast, accurate and positive. To cooperate with thearcuate supports 62, the outer side walls of the cylinder assembly areprovided with interrupted retaining means comprising spaced arcuateprojections 64. These projections are interrupted to form the notches6l), and the arcuate supports 62 subtend an `angle slightly less thanthe angle of the notches or grooves 6d so that in one rotated positionthe projections will clear cooperating grooves 66 in the supportingelements 62 while in another rotated position the projections will bebrought into engagement and cooperate to provide an .accurately fixedlongitudinal location for the entire clutch and brake assembly. Once thelongitudinal location of the assembly is xed relative to the housing 14,the circumferential location of the parts can be established in anysuitable manner, by fixing the iiuid cylinder against rotationalmovement, preferably by the locating means so that a duplication ofparts is not required.

vIn the form of the invention shown in the drawings, the fluid cylinderis held against rotation relative to the housing 14 by iiuid supplylines 68 and 70 (FIG. 3). It is, of course, possible to substitutesimple locating screws for the assembly, but so long as the fluid supplylines must be connected in any event, these lines serve the dual purposeof supplying fluid to the two sides of the cylinder 54 and locating thecylinder and assembly in the circum- -ferential position relative to thehousing 14. The fluid supply lines 68 and 70 extend through passages 72and 74 in the housing 14 and through one of the supporting members 62after which they are threadedly engaged in tapped passages 76 and 78 inthe components 5S and 56 respectively. Suitable passages are drilled inthe components which make up the cylinder assembly so that the supplylines communicate with the right and left ends of the cylinder 54, andthe passages by which fluid is admitted to and exhausted from theopposite sides of the cylinder Y are designated Si) and S2 in thedrawings.

Within the cylinder 54 is an' annular piston member 84 Y which isT-sh'aped in" lateral cross section and includes an annular pistonportion 86 and an annular ange 38 extending longitudinallypof thedrivenshaft 12, with the Vflange forming; in effect, o'ne Wall' of thecylinder in which it cooperates. The piston dois maintained influidtight relationship'with respectA to the; cylinder 54 by aperipheral sealing ring 9@ while the'longitudinal flange 88 isAmaintained in fluid-tight relationship with the y,adjacent portionsl ofthe cylinder assembly 56' and 58 by sealing rings 9i2 and 9'4. rlChethree sealing rings prevent the escape of uid from either side of thecylinder to' the other or along the annular flange.

Power Vfluid such' as air is'supplied to the cylinder 54 and the lines68 and 7) froma s'upplyline 96'which may be controlled by any suitablevalve. A manually operated four-way valve 98`is indicateddiagrammatically, and

when the valve 98 is turned to supply air to the line 68,

the lin'e 70 is connected t'o a vent liti). In this manner,Y

, when fluid is supplied' to the right endV of the cylinder 54 it pushestheV piston S6 and the flange S3 toward the left While thear from'theleft end of the cylinder is exhausted through the. vent 100; As thepiston 84' moves in this direction', the flange 88 pushes'against theinner race 50 of the bearing 46, thereby moving the retainer 42 andforcing the clutch Vdiscs 44 and 46 together to establish a drivingrelationship between the drive shaft 16, the clutch cup 20 andthe drivenshaft 12.

On` the opposite side of the' uid operating elements, a brake isprovided' which may take any suitable form` but whichyfor purposes` ofeconomy, is made up of elements very similar to the clutch discsypreviously described. The brake' assembly is' generally indicated at 102and includes a plurality `of annular brake discs'104 which rotate with'the spindle 12 through a key 106,`and aplurality of interleavedstationary brake discs S which have tabs 110 extending 'intoperipherallyispaced notches 112 in a stationary brakern'ember 114. Thebrake 'member 114 includes, a cover flange 116 which is bolted on an endof the housing M'by a plurality of machine screws 118. The brake discs16M and 168 can rotate freely relative to one another until theyareforced into braking engagement by a' pressure plate 122 which forces thediscs together and against a backing plate 129. This form` of lbrake isalso known in tionA of the housing to maintain the oil temperature at adesirable level and to dissipate heat generated by the actuation of theclutch and braking discs. The heat from the discs is transferreddirectly to the oil which is thrown over the rotating parts, and-to thisend the oil in the housing is maintained at such a level that theperiphery l of the collar 3i? and the flange 44 are immersed. Rotatheart and Vno claims are made thereto. apart from the combination. Thebacking plate 120 is held in position by a spacer '124 which abutsasupporting bearing 126 mounted in the stationary brake member 114 'andthe pressure plate 122' is free to move longitudinally over the shaft12. Y

Movement of the pressure plate 122 and actuation of the brake is causedby the entrance ofV air through lines 7) to the left end of cylinder 54which forces the piston 86' toward the right and causes thelongitudinally extending flange 88 to contact the pressure plate 122,moving it tothe right and applying a braking force to the discs 104' and108. The braking force will bring the' spindle 12 quickly toa" stop. Atthe time the brake is applied, the driven shaft 12`has already beendisconnected from the drive. shaft 16Y because the engagement betweenpiston ange 88 and the bearing 46 has been broken'by movement ofthepiston flange so that'there is no longer any pressure` applied betweenthe clutch discs 34 and 36. It will thus be seen that the spindle 12 canbe lstarted and stopped rapidly because of the lower inertia forces ofthe components.v By Vutilizing airion either side of the piston tion ofVthe parts, then, will throw oil over the entire as sembly. Y Y l Itwill be seen that the assembly so far described is capable of rapiddisassemblyandeasy access for repairs or replacementy of the clutchdiscs 34, 36, the braking discs 1494, 108, or renewal of the seals inthe iluidsystein. For this purpose, Vthe screws 118 are removedy whichWill free the outer flange 116 from the housing 14. The cover of thehousing 14 may be removed if necessary. The supply lines 68 and 70 arethen removed from the tapped holes 76 and 7S and are retracted. Theentire internal assembly may then be rotated to disengage Vtheprojections 64 from the grooves 66 i-n the arcuate supporting memberswhich remain attached tothe housing. The assembly can then be withdrawnfrom the housing through .the Vopening at the right end. If it isunnecessary to withdraw the clutchV cup 2t), this element may remainattached to the driving shaft 16. if the bearing 26 may require'renewal,it willl bedesir- Vable to disengage the setscrews 24 from the motordrive l. In a drive and brake mechanismY of the character described, thecombination of (a) a'main housing,

(l) a driven shaft, (b) a stationary bearing member,

f (1) removablymonnted in an end opening in Vonewall ofthe housing andVrotatably support- YVin'g a portion of said driven shaft extendingtherethrough,

Y (C) a drivingshaft extending into the opposite end of said housing,(d) a clutch in said main housing operable to cause driving engagementbetween saiddrivirig and driven shafts,

(e) a brake for said driven shaft disposed in said main housing andincluding (l)V portions' cooperating with'said stationary bearing memberand (2) portions keyed to said driven shaft,

( f) an annular two-faced piston surrounding the driven shaft'in saidhousing,

(1) operating in one axial position toY cause engagement of said clutch,(2)v and in another axial position to cause engag'ement of said brake,`

(g) an annular housing within said main housing forming a cylinder forsaid annular piston,

(1)V said annular housing having interruptedv re- "taining means on theperiphery thereof and forming arcuate notches therebetween, Vand (h)spaced supporting members affixed to said main` housing and'engagingsaid retaining rneansand sup,-

porting said annular housinginl a fixed axial posi?. tion relative to'said mainhousing,

( 1) said supporting members having arcuate in. terior surfacesextending circumferentially 'less than said notches whereby saidinterrupted re- However,

5 taining means and said supporting members can be engaged anddisengaged by rotational movement of said annular housing.

2. The combination of elements detined in claim 1 and means to suppiyoperating fluid to each -iace of said annular piston to move said pistonaxially bach and forth in said cylinder,

(a) said last means acting when connected to prevent rotationaldisplacement of said annular housing.

3. The combination of elements deiined in claim 1 in which said mainhousing contains cooling oil, and a cooli-ng coil in said housingimmersed in said oil.

4. A drive and brake mechanism of the character described comprising lahousing having opposite end walls, one of which has a smail diameteropening and the other of which has a large diameter openingsubstantially coaxial with said small diameter opening, a driving memberin said housing having a drive shaft extending through said smalldiameter opening of said housing, said driving member being capable ofpassing through said large diameter opening or" said housing andincapabie of passing .through said small diameter opening of saidhousing, a driven shaft projecting into said housing through said largediameter opening and having its inner end rotatably supported by saiddriving member, an annular, twofaced piston member positioned aroundsaid driven shaft in said housing and axially movable with respect tosaid driven shaft, a stationary cylinder positioned around said pistonto form opposing sealed chambers therewith on opposite sides of saidpiston, said cylinder being capable of passing through said largediameter opening of said housing, means for supplying power duid to thesealed chambers on either side of said piston, a stationary brake memberprojecting through said large diameter opening into said housing andsecured to said housing,

said stationary member being removable through said large diameteropening, said stationary member also rotatably supporting a portion ofsaid driven shaft, disc means associated with said driving member andsaid driven shaft for engaging said driving member and said driven shaftwhen power uid is supplied to said cylinder to force said piston towardsaid driving member, and additional disc means associated with saiddriven shaft and said stationary member for engaging said driven shaftand said stationary member to stop said driven shaft when power huid issupplied .to said cylinder to torce said piston toward said stationarymember, both of said disc means being capable of being removed throughsaid large diameter opening of said housing.

5. A mechanism according to claim 4 wherein said cylinder has engageablemeans on the outer surface and further characterized by means aixed tosaid housing and engageable with the engageable means of said outersurface of said cylinder to enable rotatable movement of saidcylinderand to prevent movement or said cylinder axially of said drivenshaft when in one circumferential position and to enable said cylinderto be moved toward said large diameter opening when in anothercircumferential position.

References ited by the Exner UNITED STATES PATENTS 2,159,326 5/ 39Harwood et al.

2,3 8 6,220 10/ 45 Lawler et ai.

2,7 G 1,042 2/ 5 8 Kurzweil 192--87 2,909,255 10/59l Chung.

2,930,460 3/ 60 Isaacson.

2,966,245 12/ 60 Judge.

DAVID I. WILLIAMOWSKY, Primary Examiner.

1. IN A DRIVE AND BRAKE MECHANISM OF THE CHARACTER DESCRIBED, THECOMBINATION OF (A) A MAIN HOUSING, (1) A DRIVEN SHAFT, (B) A STATIONARYBEARING MEMBER, (1) REMOVABLY MOUNTED IN AN END OPENING IN ONE WALL OFTHE HOUSING AND ROTATABLY SUPPORTING A PORTION OF SAID DRIVEN SHAFTEXTENDING THERETHROUGH, (C) A DRIVING SHAFT EXTENDING INTO THE OPPOSITEEND OF SAID HOUSING, (D) A CLUTCH IN SAID MAIN HOUSING OPERABLE TO CAUSEDRIVING ENGAGEMENT BETWEEN SAID DRIVING AND DRIVEN SHAFTS, (E) A BRAKEFOR SAID DRIVEN SHAFT DISPOSED IN SAID MAINHOUSING INCLUDING (1)PORTIONS COOPERATING WITH SAID STATIONARY BEARING MEMBER AND (2)PORTIONS KEYED TO SAID DRIVEN SHAFT, (F) AN ANNULAR TWO-FACED PISTONSURROUNDING THE DRIVEN SHAFT IN SAID HOUSING, (1) OPERATING IN ONE AXIALPOSITION TO CAUSE ENGAGEMENT OF SAID CLUTCH, (2) AND IN ANOTHER AXIALPOSITION TO CAUSE ENGAGEMENT OF SAID BRAKE,